Touch screen displays have become ubiquitous in current mobile platform applications, such as smart phones. Touch screen displays eliminate the need for key pads. In one adaptation, touch screen displays are used, not only as a replacement of key pads, but as a user interface that detects user gestures on the touch screen and translates the gestures into desired commands to be performed.
Touch screen displays are, conventionally, an LCD (liquid crystal display) technology, or an LPD (light emitting polymer display) technology. The screens are overlaid with a touch sensor, which use touch sensing technology such as capacitive, resistive, infrared, and surface acoustic wave technologies, to determine one or more points of contact with the touch screen. The touch sensing technologies, however, receive information in two-dimensions in the plane of the display. FIG. 1, by way of example, illustrates a conventional mobile platform 10 with a touch screen display 12 that detects two-dimensional touch information, i.e., along the X-axis and along the Y-axis. In other words, the touch sensor on the touch screen display 12 detects the position of contact on the touch screen display 12. Some touch sensing technologies, such as capacitive sensors, may detect how close an object is to the touch screen display 12, but ultimately determines the object to be in contact when the detected parameter, e.g., capacitance, is within a specified threshold. Thus, such touch sensing technology is really detecting only two-dimensional information, i.e., whether the object is close enough to be considered contact and if so, the two-dimensional position of that contact.
Thus, conventional touch screen displays function as a two-dimensional user interface, thereby limiting the user's interfacing opportunities and the devices response thereto.